ABSTRACT - Weebly



LABORATORY GLASSWARE

Time Line

11.15am Settle Down & Introduction

• Aim of session + to reduce injury by using good technique

• Brief discussion of what glass is & the injuries it causes. Then demo of techniques & alternates

• Discussion to share our knowledge

• Ask questions & add comments

• My credentials – BSc + Grad Dip OH, 12 jobs, 2 schools

11.20am Basics

• What is Glass?

• Types of Glass

• How glass is made

11.25am Hazards & Injuries

11.30am Demo of Techniques & Alternatives Laboratory Glassware & Special Techniques

12.15pm Washing up & stain removal

12.20 pm Final Questions

12.25 pm Finish

Laboratory Glassware

Presented by: Sheryl K. Hoffmann, B Sc., Grad Dip. O. H., MSIA

Concordia College

shoffmann@concordia.sa.edu.au

CONASTA 55

11.15am – 12.25pm Monday 10th June, 2006

University of Adelaide

DEFINITIONS OF GLASS

Glass is the transparent material that we get by melting a mixture of sand, sodium carbonate, and calcium carbonate at a high temperature, followed by cooling. When the mixture is exposed to a high temperature, the properties of the raw materials change and the mixture becomes a highly viscous liquid. When this liquid is cooled, the viscosity increases and becomes a solid material – glass. Before cooling glass can be pulled, bent or twisted to get a completely new shape.

Chemical Dictionary

A transparent or translucent material, often brittle, usually made by fusion of silica, soda ash, lime and slat cake or similar materials. Other materials are used for various special glasses. Although physically solid, glass is considered by physicists to be a super-cooled liquid, since its structure is not crystalline but amorphous, as is characteristic of liquids.

Soda glass (or ordinary glass) is typically 20% sodium oxide (from soda ash), 5% calcium oxide (from limestone), 70% silica (from sand) and small amounts of other compounds.

Borosilicate glass contains boric acid, which lowers the viscosity of silica without increasing its thermal expansion. These glasses are resistant to thermal stress and have excellent chemical durability. Borosilicate glass is often referred to by trade names such as Pyrex.

OXFORD DICTIONARY

Siliceous substance, usually transparent, lustrous hard & brittle

THE WEBSTER DICTIONARY:

Any of a large class of materials with highly variable mechanical and optical properties that solidify from the molten state without crystallization, that are typically based on silicon dioxide, boric oxide, aluminium oxide, or phosphorus pentoxide, that are generally transparent or translucent, and that are regarded physically as supercooled liquids rather than true solids.

TYPES OF FLAT GLASS

Float glass

Float glass gets its name from the method of production used to manufacture it. The molten glass is 'floated' onto a bed of molten tin - this produces a glass which is flat and distortion free.

Float glass can be cut using a glass cutter and no special equipment is necessary. Float glass is suitable for fixed and opening windows above waist height.

Toughened or Safety glass

Toughened glass is produced by applying a special treatment to ordinary float glass after it has been cut to size and finished. The treatment involves heating the glass so that it begins to soften (about 620 degrees C) and then rapidly cooling it. This produces a glass which, if broken, breaks into small pieces without sharp edges. The treatment does increase the surface tension of the glass which can cause it to 'explode' if broken; this is more a dramatic effect than hazardous.

It is important to note that the treatment must be applied only after all cutting and processing has been completed, as once 'toughened', any attempt to cut the glass will cause it to shatter.

Toughened glass is ideal for glazed doors, low level windows (for safety) and for tabletops (where it can withstand high temperature associated with cooking pots etc.

Toughened glass will not break in such a way. A toughened glass windscreen will shatter into many small pieces with small, dull edges

|Ordinary glass when broken |Toughened glass when broken |

|[pic] |[pic] |

Laminated glass

As the name suggests, laminated glass is made up of a sandwich of two or more sheets of glass (or plastic), bonded together by a flexible, normally transparent material.

If the glass is cracked or broken, the flexible material is designed to hold the glass fragments in place.

The glass used can be any of the other basic types (float, toughened, wired etc.) and they retain their original breaking properties.

Some laminated glass is laminated for other reasons than just keeping any broken glass in place, some provide decorative internal finishes to the glass while others act as fire breaks.

[pic]

Mirrors

Mirrors are usually made from float glass 4-6mm thick, and silvered on one side. Mirrors are available for use without a surrounding frame, these usually are made from a type of safety glass. Old mirrors, and modern mirrors supplied within a frame, should not be used unframed as any damage to them might cause the glass to shatter dangerously.

Transparent Mirror / Two way mirrors: When incorporated into laminated glass, transparent mirror allows for undetected observation Proper ambient light ratios are required to maximize the transparent mirror effect. On the light side most of the light is reflected back so the little light being transmitted from the dark side is not observed.

[pic]

To tell if a mirror is a normal or a two-way mirror:

Place the tip of your fingernail against the reflective surface and if there is a GAP between your fingernail and the image of the nail, then it is a GENUINE mirror. However, if your fingernail DIRECTLY TOUCHES the image of your nail, then it is a 2-way mirror.

SELF CLEANING GLASS

Pilkington now manufacture a revolutionary kind of glass that needs little cleaning. This new glass is called Pilkington Activ glass.

It has a special nano-scale - extremely thin - coating of microcrystalline titanium oxide which reacts to daylight.

This reaction breaks down filth on the glass, with no need for detergent. When water hits it, a hydrophilic effect is created, so water and dirt slide off.

The coating, which is based on titanium dioxide, works by combining the two beneficial effects. First, the ultraviolet wavelengths in sunlight react with a photocatalyst to break down organic debris on the glass.

"The second feature is that the coating is hydrophilic," says Webb. "This means that when rain hits the glass, it doesn't form droplets. Rain water flows down the glass in a sheet and washes the dirt away." Alternatively, a hose can be used to clean the glass when there is little or no rainfall.

The coating has two distinct features. It contains a photocatalyst that is activated by UV light and it is also hydrophilic. UV light reacts with the coating to break down dirt. Water coalesces to form a sheet as it flows off the glass and picks up any dirt particles on the way.

[pic]

1 Dirt, glass, Nano-scale Activ coating containing microcrystalline titanium dioxide

2 Sun shines on window. The UV rays trigger a chemical reaction in Activ coating, called a photocatalytic process, which breaks down dirt

3 When water hits glass, a hydrophilic effect is created. Water spreads evenly over the surface, instead of droplets, so runs off and takes dirt with it

WHAT INJURIES ARE CAUSED BY GLASSWARE?

WORKCOVER DATA FROM 1991/92 – 1997/98

CLAIMS GROUPED BY HAZARD / RISK in order of cost

|Cost |Type |

|$34,993.48 |Dermatitis |

|$21,323.20 |Stress |

|$11,751.55 |Glassware |

|$2731.39 |Chemical Burns |

|$694.10 |Burns, unspecified |

|$491.06 |Other Strains & Sprains etc |

|$136.90 |Animal Bites |

|$79.50 |Chemical Fumes while washing up |

CLAIMS GROUPED BY HAZARD / RISK in order of number of incidents

|Number |Type |

|4 |Cuts etc from Glassware |

|4 |Chemical Burns |

|4 |Other Sprains & Strains etc |

|3 |Animal Bites |

|2 |Dermatitis |

|1 |Stress |

|1 |Chemical Fumes while washing up |

The following cases involved glassware:

Case 2 Glass splinter to finger, $124.80, non-exempt.

Case 4 Laceration/puncture wound to palm of hand while putting glass tubing into a rubber stopper. 4 weeks off work. $2978.92, exempt employer.

Case 5, 4 months after original injury in Case 4, required surgery, as two tendons were severed in the original accident, $8433.98, non-exempt employer.

Case 6 Infection of laceration to hand, from pushing glass tubing into a rubber stopper and $179.85, non-exempt employer.

Case 7 Puncture wound to finger, $34.00, non-exempt employer.

Case 9 Chemical burn and glass fragment in eye, $984.54, non-exempt employer.

Case 11 Acid burns to upper forearm and stomach, flask broke while diluting sulfuric acid, $1020.25 non-exempt employer.

Case 12 Acute exposure to unknown chemical fumes, while washing glassware, $262.00, non-exempt employer.

Case 13 Allergic reaction to spider bite, spider inside rubber glove while washing glassware, $0, exempt employer.

Case 21 Acid burn to eye from 2 M Sulfuric Acid, stopcock came loose while repairing leaking voltameter, $32.50, non-exempt employer

Case 24 A glass fragment embedded in the finger, cost $169.

DATA FROM UNIVERSITY OF SUSSEX 1982-1983

Glassware accidents account for 10% of all reported accidents in the University.

Main causes:

• 24% due to pipettes breaking during insertion to pipette holder

• 30% due to handling already broken glassware that should have been withdrawn from service

• 27% due to mishandling glass tubing or rod eg not protecting hands, stirring too violently

• 6% due to cleaners attempts to sort waste that contained glass

• 6% due to glassware being dropped

LABORATORY GLASSWARE

Two main types of glass used:

1. Soda-lime

2. Borosilicate eg Pyrex

Laboratory glassware can be divided into 5 main uses:

1. To heat & mix eg beakers, conical flasks, test tubes

2. To store eg reagent bottles, Polystop bottles

3. To transfer eg Pasteur pipette, delivery tubes

4. To deliver a specific volume eg measuring cylinder, graduated or volumetric pipette

5. To contain a specific volume eg volumetric flask

6. Special Applications

USES AND ALTERNATIVES

1. TO HEAT & MIX

Beakers

• Don’t fill beakers completely full. Eg If you need to make up 500ml of solution a 500 ml is too small. Use the next size (eg 600ml)

• Tall beakers are sometimes more useful than squat ones eg 600ml

• Badly scratched beakers are more likely to break & should be removed from use

• Use a policeman on one end of a stirring rod to prevent scratching

Conical Flasks (or Erlenmeyer Flasks)

Test Tubes

• Rimmed boiling test tubes often chip especially when putting in dishwasher baskets

• Unrimmed test tubes may fall through test tube holders

• Test tube Holders large peg type, wire type or pegs

• Test tube racks are usually only made to fit one size of test tubes

• ½” test tube is the next most useful size

• microtest tubes come in reusable & disposable

2. TO STORE

• Place a small piece of paper in the neck of Reagent Bottles when they are stored to prevent stoppers getting stuck

• Schott bottles are a better alternative to reagent bottles

• Plastic bottles with vents should be used for Hydrogen peroxide

• Specimen jars come in all sizes

• Polystop bottles a best for stains, organic solvents & conc acids

• Plastic dropper bottles may concertina when dropped and squirt solution in your face, so never put concentrated acids in them.

3. TO TRANSFER

• Pasteur pipettes should be held correctly

• Plastic transfer pipettes should be used whenever possible instead of glass ones

• Filter funnels have a different shape to domestic funnels

• Filter funnels with internal ribs are best for filter papers

• Powder funnels are useful for transferring solods

4. TO DELIVER A SPECIFIC VOLUME

Pipettes

• When using graduated pipettes fill to required volume & deliver all

• Touch the pipette to the side of the vessel for 10 secs to deliver correct amount do not blow out

• A teat can us used with 1 ml pipettes

• A syringe connected with rubber tubing makes a cheap pipette filler

• Volumetric pipettes on deliver one specific volume

Measuring Cylinders

• Cylinders with hexagonal bases don’t roll off the bench

• Plastic bases should be removed before placing in the dishwasher

• Quality issues Bomex vs Simax

5. TO CONTAIN A SPECIFIC VOLUME

• Volumetric flask are designed to contain a specific volume & not to deliver that volume

6. SPECIAL APPLICATIONS

• Capillary tubing can be used to spot samples during chromatography

• McCartney bottles are great for microbiology, live specimen cultures and just about everything else. (almost unbreakable)

• Plastic vials are an alternative

• Plastic Petri dishes are a good disposable alternative

• Buchner flask gaskets available from Science Supply Australia (listed as Gooch rubbers)

• Kipp’s Apparatus is useful when lots of gas is required

• Gas collection is best done with glass trough, beehive shelf and gas jar

• With gas collection use plastic tubing rather than glass – easier, safer & more flexible

• Don’t waste time washing coverslips – too dangerous

• Washing microscope slides is a waste of time (replacement cost vs tiem to wash & polish)

OTHER TIPS

• ONLY ever use a piece of laboratory glassware for what it was designed to do

• NEVER heat measuring cylinders, volumetric flasks and reagent bottles. They are not designed to be heated & will break. When making up exothermic solutions (eg sodium hydroxide), they are best partially make in a beaker, allowed to cool & then transferred to the volumetric flask.

• Disposable plastic or glassware saves time & reduce injuries from washing

• Buy an ‘enclosed’ Winchester Carrier, so if you drop it, the contents don’t spill.

• If using real Glass Wool wear rubber gloves. Wash your hands with a dry cake of soap to remove splinters if you forget!

• Hold a graduated or volumetric pipette against the side of the vessel for 3 seconds to ensure the correct quantity is delivered. Don’t blow out the remaining drop unless the pipette is marked “BLOWOUT”

• When making a solution ‘up to the mark’ in a Volumetric Flask be sure that the solid has completely dissolved & is well mixed. The surface above the mark (including the bottom of the stopper) should have been ‘wetted’ by the solution.

• When pouring solutions out of a labelled bottle pour away from the label so if you dribble the label is not damaged.

• When pouring out of a Winchester or reagent bottle don’t rest the bottle on the top of the measuring cylinder or beaker

• Glass becomes more brittle with age, so don’t store in bulk

• Always carry long lengths of rod or tubing in the vertical position

• NEVER pick up broken glass with your fingers (even the large pieces). Use a broom & dustpan or forceps.

• Parafilm is a good alternative to stoppers

GLASSWARE ALTERNATIVES

• Plastic beakers & measuring cylinders

• Schott bottles with lids rather than Reagent Bottles

• 4 mm Plastic tubing instead of glass tubing for gas delivery

• Burettes with Teflon taps are better than all glass taps

• Store glass bottles of mercury (for students to see what mercury looks like when doing “Elements”) in a plastic beaker

• Plastic transfer pipettes instead of Pasteur pipettes

• McCartney Bottles

Other Dispensing Equipment

[pic] [pic]

Diji Pipette Bottle Dispensers

[pic] [pic][pic]

Finnpipette Kipp’s Apparatus

SPECIALIST TECHNIQUES

Rejoining thermometer columns: Most dangerous to least dangerous:

1. Swing the thermometer rapidly in a circle but don’t snap your arm because the thermometer may break.

2. Hold thermometer vertically and gently tap the bulb on a firm surface.

3. Heat very gently holding well above a Bunsen flame. The column will be forced into the upper expansion column & when cooled it should be rejoined.

4. Place thermometer bulb in an oil bath & gently heat until the column will be forced into the upper expansion column & when cooled it should be rejoined.

5. Place thermometer bulb in crushed solid dry ice until the column withdraws into the bulb, then remove it & allow to re-warms.

6. Place thermometer bulb in acetone into which small pieces of crushed dry ice have been added until the column withdraws into the bulb, then remove & allow to re-warms.

7. Throw the thermometer out

Stuck joints

1. Gently tap the frozen stopper. Tap so that the direction of force will cause the stopper to come out.

2. Gently heat the bottle neck under warm running water. The neck should expand slightly freeing the stopper.

3. Use a piece of string wrapped around the neck & friction to heat the neck.

4. Soak the bottle in hot dilute glycerine

5. Soak the bottle overnight in Coke.

6. Throw the item out!

Inserting glass tubing into a stopper

1. Select the right size hole & tubing

2. Always apply a little lubricant onto the glass tube before inserting into the rubber stopper. Glycerine is ideal for this purpose

3. Grip the tubing close to the stopper (not greater than 10 mm), pushing the tubing into the stopper 10 mm at a time. Rotating the tubing often makes it easier. Pushing by gripping at even 4 cm from the bung may snap the tubing. Never push the tubing with your palm.

4. If the tubing doesn’t go in easily don’t force it.

Removing glass tubing from a stopper

1. Always apply a little lubricant onto the glass tube before trying to remove rubber stopper. Glycerine is ideal for this purpose.

2. Grip the tubing close to the stopper (not greater than 10 mm), and pull with a twisting motion. Never try to push the tubing through with your palm.

3. If the tubing doesn’t come out easily don’t force it. Instead us a hack-saw to cut along its side to the depth of the tubing. Open bung to remove tubing. Never use a knife.

Inserting glass tubing into plastic tubing

1. Select correct size of tubing for the glass tubing

2. Soften the end of the plastic tubing in hot water

3. take care that you drain the hot water well before attaching the plastic tubing to the glass tubing

Removing plastic tubing from glass tubing

1. never use force

2. cut plastic away with a knife

ENCLOSED WINCHESTER CARRIER

Nalgene 6501-2500 Safety Bottle Carrier from Biolab $83.75 (2002)

BURETTE & PIPETTE WASHER

[pic] [pic]

Nalgene DS5240 Pipet Washer-Rinser

Washer-rinser fills & flushes water through the pipettes, repeating automatically.

(For pipets up to 813 mm; 32 in. long)

Nalgene now sold by:

Interpath Services Pty Ltd

Head Office

Unit 1/46 Sheehan Road

West Heidelberg Vic 3081

PO Box 340

Ph: (03) 9457 6277

Fax: (03) 9458 4010

Email: info@.au

Freecall 1800 626369

Freefax 1800 658210



in South Australia

Kathy Wilkinson

Ph: 0412 537 714

Email: kwilkinson@.au

WASHING UP & STAIN REMOVAL

It is best to rinse glassware immediately after use to prevent stains or stuff drying on the glassware making them more difficult to clean. OHSW Regulations require that items are labeled if they contain a hazardous substance until washed. So encourage students to rinse all glassware before putting it in the washup.

Soak glassware overnight in a laboratory glassware cleaner eg Pyroneg or Decon 90

Rinse with lots of water scrubbing with a bottle brush if needed. If stains or soiling persist, soak overnight again in a stronger solution.

Some Stains require specialist treatment:

IODINE: soak in 25 g/L sodium thiosulfate solution

POTASSIUM PERMANGANATE: Rinse with acidified sodium metabisulfite solution or hydrogen peroxide

IRON / RUST: Soak in conc Hydrochloric Acid or use CLR

CALCIUM HYDROXIDE / LIME WATER: Hydrochloric Acid or CLR

PERMANENT TEXTA MARKS: rub with a nylon scourer

GLUE FROM STICKY LABELS: Eucalyptus Oil or De-Solv-It™ (use only in fumecupboard)

Tips:

Some stains eg blood or proteins will bake on if treated with hot water

USING A DISHWASHER

Follow the manufacturer’s instructions. Most laboratory dishwashers require objects to be confined in baskets or on special racks to prevent objects moving.

Before putting items into the dishwasher remove sticky labels and rinse off any solids, flammable liquids or corrosives substances. (NB: Flammable liquids & corrosives may damage the machine – see the manufacturer’s instructions)

[pic] [pic]

SUPPLIERS, WEB SITES

Miele Australia : .au

The G7804 underbench model (Anything else is a compromise)



Miele USA has more pictures



Diji Pipette



Livingstone International

School’s Catalogue

Phone: 1300 855 988

Fax: 1300 729 729

Email: school@.au

Web Site: .au

General Catalogue

Phone: 1300 780 078

Fax: 1300 780 008

Email: laboratory@.au

Web Site: .au

Science Supply Australia

10 Redland Drive

MITCHAM VIC 3152

OR

PO Box 465

GLEN WAVERLEY VIC 3150

Phone: 1300 857 544

Fax: 1300 857 533

Email: sales@.au

Web Site: .au

Southern Biological

19-21 Worrell St

PO Box 57

NUNAWADING VIC 3131

Phone: (03) 9877 4597

Fax: (03) 9894 2309

Email: sales@

Web Site:

LABORATORY GLASSWARE

LIST OF ITEMS TO TAKE

Safety Glasses

Labeled sample of Soda Glass rod or tubing

Labeled sample of Pyrex glass rod or tubing

Sample of:

• Calcium Oxide

• Sand

• Boric Acid

• Sodium Carbonate

Flat Glass

Mirror

Funnels

• plastic domestic

• powder

• normal glass

• ribbed plastic

• normal plastic

Gas Collecting Setup:

• trough

• beehive shelf

• 2 gas jars & lids

• tubing

Boiling test tube stopper with PVC tubing for gas delivery

Buchner Flask, funnel & gasket + spare gasket

Parafilm (1 piece per participant)

Test tubes

• rimmed boiling

• not rimmed boiling

• ½”

• micro – disposable

• micro – thick wall

• holder – wire type

• holder – large peg type

• rack – white plastic coated wire

Plastic dropper bottle

Polystop bottle

3 mm tubing (aquarium)

600 ml beaker

250 ml conical flask

Measuring cylinder

• plastic base

• hexagonal glass base (Simex)

• round base (Bomex -thin & cheap)

• plastic

Plastic beaker

Scratched beaker

Stirring rod with policeman

500 ml Volumetric flask

specimen jar

100ml Schott bottle

Solid bottle

Reagent Bottle with paper in neck

McCartney bottle

Plastic vial

Vented plastic bottle for H2O2

Pipette filler – pi-pump

Pipette filler – 2ml syring

Pasteur pipette

Plastic pipette

Teat

1ml graduated pipette

10 ml graduated pipette

25 ml volumetric pipette

Microscope slide

Cavity Slide

Coverslips

Plastic microscope welled slide

Glass cutter

Tubing cutter

Triangular file

Glass tubing to cut

Glass tubing to insert into a rubber stopper

Stopper with short piece of glass tubing

Plastic tubing to match above

DB – glycerine

Flame spreader

Capillary tubing

Petri dish – plastic

Bent tubing for simple distillation

Bend tubing for collecting gas from micro test tube

White board marker & chalk

Optional Extras

Thermometer with column separated

Dry ice

Acetone

Plastic beaker

Winchester Carrier

Kipp’s apparatus + Marble chips + 5M HCl + tubing to trough

Beaker stained with:

• lime

• rust

• potassium permanganate

Solutions to clean stained beakers:

• CLR

• conc HCl

• H2O2

Annealing

Process by which a hot glass item is (after completion) uniformly re-heated and then gradually cooled down over many hours, in order to toughen it and make it less likely to crack when subjected to changes of temperature

Types of glass



Glossary





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